Army Staff Sergeant Robert Bales was charged with 17 counts of murder, assault and a string of other offences in the massacre of Afghan villagers as they slept.

The charges against Sgt Bales include 17 counts of murder, six counts of attempted murder and six counts of aggravated assault as well as dereliction of duty and other violations of military law.

The 38-year-old soldier and father of two who lives in Lake Tapps, Washington, was charged with going on a shooting rampage in two villages near his Southern Afghanistan military post in the early hours of March 11.

He is accused of gunning down nine Afghan children and eight adults and burning some of the victims’ bodies.

The charges reflect the change that increased the number of Afghans killed in the shooting spree from 16, which was widely reported for the past week, to 17.

There was initial confusion about the number of dead, hampered to some degree by the fact that some may have been buried before US military officials arrived at the scene of the carnage.

Defence officials said that investigators have now determined that there were 17 killed, but they were unable to provide any other details about how the change came about. Six Afghans were wounded in the attack.

Sgt Bales is being held in a military prison at Fort Leavenworth in Kansas and faces trial under the Uniform Code of Military Justice.

The killings were yet another blow to US-Afghan relations, following a series of mis-steps, including the burning of Korans, which prompted violent protests and revenge killings of American troops in the war zone.

The brutal shooting rampage also prompted renewed debate in the United States about health care for the troops. They have experienced record suicide rates and high rates of post-traumatic stress and brain injuries during repeated deployments over a decade of the wars in Iraq and Afghanistan.

Afghan officials have asked the United States for some role in the criminal proceedings, perhaps as observers, and to be kept up to date on the process of the case.

The government of Afghan President Hamid Karzai has not demanded that Sgt Bales be turned over to the Afghan justice system, although some in the country’s Parliament did.

The Afghans also have urged a fast resolution of the case.